COMBINED ENZYME AND ANTIMICROBIAL SUSCEPTIBILITY PROFILES OF CAPRINE PASTEURELLA-HAEMOLYTICA SEROVAR-2 RESPIRATORY-TRACT ISOLATES

The present investigation describes a novel method of demonstrating st rain diversity among Pasteurella haemolytica biovar A, serovar 2 (PhA2 ) nasal turbinate isolates from a flock of 32 experimental goats durin g a naturally occurring outbreak of pasteurellosis. After a 21 day con ditioning period in a feedyard, 51 PhA2 isolates from 27 culture-posit ive goats were identified including 1 on day 22, 14 on day 25, 21 on d ay 39, and 15 on day 66. Each PhA2 isolate was evaluated for its enzym e activity against 19 substrates with a commercial semiquantitative en zyme system and for its antimicrobial susceptibility with 12 drugs, re sulting in 7 different enzyme profiles and 8 different antimicrobial s usceptibility profiles. A total of 14 combined enzyme and antimicrobia l susceptibility profiles were produced. The same PhA2 strain was isol ated from only 4 of the 12 goats with 2 PhA2 isolations, while the sam e PhA2 strain was isolated from only 1 of the 6 goats with 3 PhA2 isol ations. The data from this investigation demonstrated that the PhA2 up per respiratory tract flora from goats is highly heterologous.